I don't doubt that people flip out. I don't even doubt that thousands of people among the millions who served in the military have flipped out.
What I'm wondering about is whether otherwise undamaged people who repress their emotions eventually go nuts, or whether people who control their emotions end up in control of their emotions.
People who eat small portions generally don't suddenly devour a turkey. People who only have one drink a night one night a month don't suddenly become alcoholics. Self-control doesn't necessarily mean that a problem compounds; it can be the solution to a problem, instead.